System and method for cryptographic communications using permutation

Abstract

The present invention discloses a system and method for cryptographic communications. It may significantly improve operation efficiency of existing symbol level encryption algorithms by permutating at symbol sequence level with significantly less computational requirements. The system includes a communications channel, at least one terminal with encoding device and at least one terminal with decoding device. A message comprising ordered symbols can be partitioned into ordered symbol sequences. Then the order of symbol sequences is permutated by the encoding device. The partition and permutation can be repeated recursively on the resultant symbol sequences to obtain the ciphertext. All the partition and permutating information are characterized by a secret key, used for decoding on the receiving terminal. It is required that the final resultant symbol sequences in the ciphertext should not disclose information confidentiality. The present invention can be also applied to secure distributed data storage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of provisional patent application No. 61 / 065,591 filed on date Feb. 13, 2008, “A System and Method For Cryptographic Communications Using Permutation”.FEDERALLY SPONSORED RESEARCH[0002]Not ApplicableSEQUENCE LISTING OR PROGRAM[0003]Not ApplicableUS PATENT REFERENCES [0004]1. U.S. Pat. No. 4,405,829 September 1983, Rivest, Ronald L. et al, Cryptographic communications system and methodBACKGROUND OF THE INVENTION[0005]1. Field of the Invention[0006]The present invention relates to a cryptographic communications system and method.[0007]2. Description of the Related Art[0008]Data privacy and security have been increasingly important in generation, exchange and storage of information. Data transmitted over communications channels are susceptible to interception, eavesdropping and modification. Computer networks and internet can be monitored, accessed without permission. Due to various reasons, data storage d...

AI Technical Summary

Benefits of technology

[0027]To obtain ciphertext C, the encoder permutates all symbols in M according to predefined ordering information (pk, . . . , p2, p1), which is a permutation of (k, k−1, . . . , 1). pi is the position of symbol mi in ciphertext C, where 1<=i<=k. The k-tuple (pk, . . . , p2, p1) is defined as the secret encryption key. There are a plurality of approaches to reduce the size of the secret key shared by both the encoding device and the decoding device.

[0040]Assuming M is partitioned into n symbol sequences, the number of possible combinations is factorial n!, which is larger than any exponential function in n. If the resultant symbol sequences are further partitioned and permutated, the complexity of encryption is further confounded. Therefore, assuming the resultant symbol sequences do not leak message confidential information, without the knowledge of the secret key, it is computationally infeasible to decode the ciphertext with current computing technology. As a result, symbol sequence level recursive partition and permutation provides sufficient information security for applications with no symbol level security requirement.

[0041]The partition and permutation information is used as encryption and decryption key. In some applications, a shared secret encryption key is established between the transmitter and the receiver per session basis. In this case, a distinct key is required for a separate communications session. This distinct encryption key can be encoded by other encryption techniques such as public key encryption techniques, thereafter being transmitted over the communications channel to the intended receiver. For this reason, it is important to shorten or reduce the size of the secret key.

[0042]There are a plurality of methods to shorten or reduce the size of the shared secret encryption key. For instance, same partition and permutation schemes can be applied, thus no need to transmit multiple partition and permutation information as the secret encryption key.

[0043]Alternatively, some conventional data compression techniques or hashing techniques can be applied on the secret encryption key to reduce the size of the key. When received by the intended receiver, the size-shortened key is converted back to the original secret key, which is applied on the decoding device.

Problems solved by technology

Data transmitted over communications channels are susceptible to interception, eavesdropping and modification.

Due to various reasons, data storage devices may be accessed undesirably.

These encryption algorithms involve extensive arithmetic operations and bit / symbol substitution, therefore, require substantial computing power.

Fundamentally, the daunting computing cost is due to the fact that all current transformations and mathematical operations are performed at symbol / bit level to prevent bit / symbol level security breaches.

Current encryption algorithms would encode the binary executable at bit level, which would be time consuming.

Thus, without knowing the secret key, it is computationally infeasible to restore the order of the re-ordered 64 1-kilo-byte bit sequences and obtain the original binary executable using current computing technologies.

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